Areas of Research

The Group activities can be divided into the following research directions:

High-Power Ultrafast and CW Quantum Dot Edge-Emitting Lasers

Portable, low-cost, reliable and highly-efficient CW and ultrashort pulse Near-IR (1µm-1.3µm) laser sources based on quantum-dot semiconductor structures. Part of this work was funded by FAST-DOT, €14.7M European project involving 18 partners (2008-2012) and by People Marie Curie Action project NiNTENDU-PULSE (2011-2013).

Research in novel, compact femtosecond lasers and their application to two- photon, second harmonic and third harmonic imaging in fixed and live tissue samples.

Quantum Dot and Quantum Well Semiconductor Disk Lasers

Compact, low-cost, reliable and highly-efficient CW and ultrashort pulse Near-IR (1µm-1.3µm) Vertical-External-Cavity Surface-Emitting Lasers based on quantum-dot and quantum-well semiconductor structures. Part of this work was funded by FAST-DOT, €14.7M European project involving 18 partners (2008-2012).

High-power SESAM-free mode-locked QD- and QW-VECSELs.

Room-temperature mid-IR Quantum Cascade Lasers

Broadly tunable room-temperature mid-IR Quantum Cascade lasers (3.2µm-3.3µm) for the use in compact spectroscopic gas sensing system, free space communication, atmospheric sensing, environmental monitoring and detection of dangerous substances (like CO, N2O, HCL, CH2O, CH4).

Efficient Nonlinear Frequency Conversion into the visible spectral region

Compact, efficient, broadly tunable visible laser sources (500 nm — 650 nm). Part of this work was funded by the FAST-DOT, €14.7M European project involving 18 partners (2008-2012).

Research in broadly tunable continuous wave and picosecond lasers and their application in Confocal Laser Scanning Microscopy (CLSM) and Fluorescence Lifetime Imaging Microscopy (FLIM) with a focus on quantitative imaging in biological samples.

Novel quasi-phase-matched semiconductor nonlinear crystals for generation of IR radiation

Generation of UV-visible and IR/mid-IR radiation using novel quasi-phase-matched nonlinear waveguided crystals based on different semiconductors. This work was funded by EPSRC (2006-2009).

Generation of THz radiation

The development of ultra-compact, room temperature sources of coherent THz radiation. This work is based primarily on the optimisation of devices and structures based on quantum-dot semiconductor materials, as well as traditional materials such as low-temperature-grown GaAs and InGaAs. This work was funded by EPSRC (2010-2013).

The fabrication of low-cost, compact, room-temperature terahertz sources emitting few tens of µW powers at 0.3–1.5 THz and beyond for Safety and Security applications, Quality control, Biophotonics, and medical imaging, with the particular application of THz radiation for the non-invasive and non-spreading diagnose and investigation of superficial cancers (skin cancers, gastric cancers, cervical cancers, colon cancers, etc.). This work is funded by €1.1M TERA EU-FP7 Project (2012-2016) and FP7 project NEXPRESSO.

Laser Diode Spectral Shaping

Optical schemes for stable single and dual-wavelength operations of laser diodes, using volume Bragg gratings and fibre Bragg gratings. Dual-wavelength operation is particularly desirable for terahertz difference signal generation and for super-resolution microscopy.

Generation of two optical modes in the IR and visible spectral region with a tuneable difference frequency between 0.3THz and 33 THz.

Laser Diode Beam Shaping

Development of novel techniques for shaping the laser beams (Conical Refraction, Bessel Beams, etc.) producing unique optical properties for micro-machining, materials processing and life sciences applications.

Conical Refraction investigation was funded by €1.7M HiCore Project (2012-2014).

Work on Bessel Beams was funded by People Marie Curie Action project SeNDBeams (2010-2012).

Highly Efficient and High-Brightness White LED Sources

The development of high efficiency and high brightness monolithic and hybrid all-semiconductor WHITE light-emitting GaN-based diodes with the aim to replace conventional light sources with superior highly efficient white LEDs. This work is funded by €11.8M FP7 IP program called NEWLED.

Biophotonics for Non-invasive Diagnostics and Treatment

Amongst our research interests is the therapeutic potential of novel and compact near-infrared diode lasers in the context of photo-medicine, particularly in new forms of photodynamic therapy (collaboration with the Scottish Photodynamic Therapy Centre at Ninewells Hospital (Dundee), in this research direction.

Multi-functional non-invasive laser diagnostics systems for the optical analysis of blood and biological tissues using several non-invasive diagnostic methods, including Laser-Doppler Flowmetry, Tissues Reflectance Oximetry, Laser Fluorescence Diagnostics, and pulse oximetry method. The main application areas in medical practice are Angiology and Physiology, Transplantation, Gastroenterology, Oncology and Radiology. This research was funded by €1.7M FP7 IAPP project called MEDILASE, and is partially funded by FP7 IDP project called PHOQUS (value €3.8M).

Advanced diagnosis and treatment of bladder cancer. The project is based on results which show that cancerous cells may be identified under infrared light analysis, and infrared lasers developed here may be implemented as part of the project. This research is funded by €2.4M FP7 IAPP project called ABLADE.